PURPOSE: To simplify the circuit constituion and make the display easy to read, by counting the time in the second time counting means in respect to selected contents out of plural additional functions stored in a storage means and switching the means from normal main and subdisplay means to the second time counting means to display contents of the second time counting means when the function is selected.

CONSTITUTION: The output of a quartz oscillator 1 is given to a counter 4 for time counting and a counter 5 constituting the second time counting means through frequency dividers 2 and 3. Latch circuits 6W8 constitute storage means for alarm time set, timer, and stopwatch respectively, and outputs selected by gate circuits 9 and 10 are displayed on main and subdiscplay means 13 and 14 through decoders 11 and 12. A rotary swich 52 selects the time adjustment, the alarm time set, the timer, or the stop watch, and a lock swtich 56 and forward setting switches 57 and 58 are operated to control the data transfer between counters 4 and 5 and circuits 6W8; and the current time and the alarm time are displayed on means 13 and 14 respectively normally, and a selected function and the current time are displayed on means 13 and 14 when the function is selected.